Germany publishes orientation values for «technically avoidable» metal content to be used in cosmetics products. Heavy metals are banned in cosmetics under EU law, but traces are allowed if the amount is small enough to be technically unavoidable and does not present a danger to human health. There are no specific limits, however. Calculating acceptable values for human health is not as simple as metals are widespread everywhere and the risk threshold and floating range of cosmetic typology.

Inside European Regulation
The metals are distributed more or less uniform in the environment around us, they are spread in rocks and in the earth’s crust and present in foods and water. Just a due to their almost ubiquitous presence in the environment, it is practically impossible avoid them completely. Regarding the presence of heavy metals in cosmetics, European legislation has taken into account their wide diffusion in the environment. European Regulation no.1223/2009 / EC, admits the presence of metals in the finished products if technically trace are inevitable. Such presence shall be tolerated only if they have been respected good manufacturing practices and, above all, a provided that the end product is safe in the product normal and predictable conditions of use, following the evaluation carried out by security assessor. However, in the regulation there are no precise limits, the quantity of metals tolerated in a cosmetic product is related to the general principle of evaluation of risk.

Ensuring the absence of heavy metals
The task of the cosmetic formulator is to use raw materials whose chemical and physical characteristics and technical specifications guarantee the lowest possible level of impurities of prohibited substances, including heavy metals. To this will be added a special assessment of the safety of the human health of the product, by a security assessor in possession of the securities required by the norm and appointed by the product manager. The evaluation shall take into account the general toxicological profile of the ingredients, their chemical structure and exposure level. The safety assessor should investigate the toxicity of each present substance and the finished product, based on this assessment of the presence (or not) of any impurities or traces of prohibited substances. In its final report, the safety assessor must of course justify the safety of the product, considering also the presence of any impurities or technically unavoidable traces of banned substances.

Analytic methods
For the purpose of control, the method used for the preparation and analysis of the sample for the qualitative/ quantitative research of heavy metals in finished cosmetic products is of paramount importance, especially where it is desired and analyzed the presence of metals in different oxidation states, which result in different levels of danger (the need to differentiate between chromium III and chromium VI). It is not rare in cases where analytical results are inaccurate for difficulties in sample preparation. On the other hand, the optimal conditions for the analysis of metals in various complex cosmetic matrices are not easily predictable and predictable. That of the analytical method remains an indispensable problem to be faced, where there is the interest and willingness of the cosmetic producer or legislator to set maximum limits for the presence of heavy metals in finished cosmetics.

Risk assessment
Regardless of the analytical methods used to quantify the presence of heavy metals, the most important element is definitely the threshold value that guarantees the safety of the cosmetic. what are the parameters that allow you to evaluate the risk? MoS is used for cosmetic products. MoS is the ratio between NOAEL and SED. The NOAEL (No Observed Adverse Effect Level ordose without any adverse effect observed) higher concentration or amount of one substance, expressed in mg / kg body weight, derived from experimental studies, preferably in the long term, or epidemiological observations, which does not cause toxic (adverse) effects, alterations morphological or functional, modifications of the bodily growth, development and duration of the life of the experimental subject in the studio. The SED (Systemic Exposure Dosage, dose of systemic exposure) of a cosmetic ingredient is the amount you are supposed to enterblood flow (and therefore be availablefor the whole organism) per kg of body weightper day. It is expressed in mg/kg body weight/day (average body weight = 60 kg). The ratio between these two parameters allows extrapolation of the safety data related to the presence of heavy metal in a cosmetic preparation. MoS do not have to absolutely to be considered onetoxicity threshold but a safety threshold. Based on these parameters it is possible to establish concentration values of heavy metals that can be tolerated in a different kind of cosmetic. See table 1 the values calculated in this way are indicated by Scientific Committee Consumer Safety (SCCS). In the model of SCCS were used absorption data oral and non-cutaneous, so these values for cosmetics can be considered even safer, as skin absorption is much lower than oral absorption.

Germany and orientation values
In the years 1990, the Cosmetic Commission of the German Federal Health Office (BGA) published values for technically avoidable levels (BGA 1985, 1990). These orientation values were considered outdated by the preliminary Commission for Cosmetics in2005, since it was expected that the levels of heavy metals have declined in cosmetic products; therefore, lower technically unavoidable levels are achievable by applying good manufacturing practice. Potential heavy metal contaminations can be expected particularly in cosmetic products containing high levels of inorganic or mineral components, especially powder and cream products, decorative cosmetics and toothpastes. The German Monitoring Scheme is a system of repeated representative measurements and evaluations of levels of substances which are undesirable from a health point of view. From 2010 to 2012, the commission for cosmetic created a data basis to derive current representative orientation values with an adequate sample size within all relevant product categories.

Lower the threshold: the study
The tolerance threshold was lowered after a commission surveyed about 2000 different cosmetic products from all over Europe. Lipstick, mascara, eyelid line, eye liner, kajal, eye shadow, tinted cream, camouflage, rouge as well as theater, fan or carnival make-up, children’s toothpaste and toothpaste were analyzed for the elements lead, cadmium, mercury, arsenic and antimony. The determination of the elements was conducted with a standardized convention method, bringing the elements under defined conditions into solution. This study has made it possible to re-calculate the tolerance parameters, demonstrating that now the methods for producing cosmetics are so sophisticated to significantly reduce the presence of heavy metals.

Heavy metals and health risks
Having maximum concentration limits for heavy metals guarantees a certain degree of safety, even though heavy metals are harmful to human health, and in any case cosmetics should be as small as possible. In the case of metals there may be a difference between the quantity that may be considered «technically unavoidable» and that which can be considered «safe» for human health. This is because even small amounts of metal content in the cosmetic after prolonged exposure to the cosmetic itself may cause long-term effects. the limits calculated according to the ssgc system if respected will put consumers away from the systemic toxicity a different discourse relates to local reactions, which manifest themselves as irritation or allergy. Several of the metals considered have propertiesirritants, but behave differently depending on the matrix they are in. in cosmetics for establish a security threshold, you have to determine how much metal can actually come into contact with the skin and be, therefore, available for absorption. Furthermore, this value would still have a meaning different depending on the cosmetic product, because the type of exposure, and then the bioavailability, may be different (in others words if a X concentration of a metal Y may be irritating in a lipstick, the same concentration can be harmless in one nail polish, a lacquer for hair, one bath foam ecc.). It becomes quite impossible for the legislator to set a threshold and adapt it to a different cosmetic. For this reason the risk should be considered case by case and it is referred to as guiding values.

References
–The New EC Cosmetics Regulation 1223/2009 – IKW
–Guidance on Heavy Metal Impurities in Cosmetics – Canada.ca

by Elisa Brunelli, PhD Biotechnology